Groom flickering when two characters are visible at the same time

https://youtu.be/7x3yZW2mE6Y
Hello as you can see in the video attaached, i've got two skeletal meshes and the groom is flickering on both, if i turn one of them off ( visiblity ) the flickering on the other groom stops.
How can i solve it please?
I'm on unreal 5.5.3 .
Many thanks!!